Fire-control means for aircraft machine guns



Se t. 4, 1923. 1,466,951 D. G. EDWARDS FIRE CONTROL MEANS FOR AIRCRAFT MACHINE GUNS Filed March 29 1919 3 Sheets-Sheet 1 Sept. 4, 1923. 1,466,951

D. G. EDWARDS FIRE CONTROL MEANS FOR AIRCRAFT MACHINE GUNS Filed March 29, 1919 3 Sheets-Sheet 2 J6 /7 Y 4Z4 7/.6. 7/ .5.- g 26 25 Snow Wot Sept. 4, 1923'. 1,466,951

* D.G. EDWARDS FIRE CONTROL MEANS FQR AIRCRAFT MACHINE GUNS Fiiled March 29, 1919 3 Sheets-Sheet 5 2 g nvemboz Patented Sept. 4, 1923.

UNITED STATES PATENT OFFICE.

DANIEL G. EDWARDS, OF HOPKINSVILLE, KENTUCKY, ASSIGNOR TO J. AUSTIN STONE, OF WASHINGTON, DISTRICT OF COLUMBIA.

FIRE-CONTROL MEANS FOR AIRCRAFT MACHINE GUNS.

Application filed March 29, 1919. Serial No. 286,131.

To all whom it may concern:

Be it known that I, DANIEL G. EDWARDS, a citizen of the United States, residing at Hopkinsville, in the county of Christian and State of Kentucky, have invented new and useful Improvements in Fire-Control Means for Aircraft Machine Guns, of which the following is a specification.

My invention relates to the control of the fire of machine guns mounted upon aeroplanes in position to shoot through the plane of revolution of the propellers and between the blades.

When a machine gin is mounted upon an aeroplane, or other aerial vessel, in such a position as to fire between the blades of the revolving propeller, the control of the discharge of the gun must be absolute and positive in order to avoid injuring the blades, and this should be true at the various speeds of the propeller.

The principal objects of the invention are to provide a control for the firing of the gun, or guns, in which control the action is always positive and certain; in which the mechanism may be easily taken care of and adjusted; in which there is no lag in the transmission of the control impulse from the mechanism to the gun; which will allow the gun, or guns, to be placed in any position with reference to the engine driving the propeller; in which the maximum rate of fire may be obtained at all speeds of revolution of the propeller; in which the gun, or guns, may be horizontally and vertically adjusted for aiming and the firing time changed in accordance with such adjustment and this irrespective of the speed of the propeller.

These and other objects will more fully appear hereinafter.

In carrying my invention into effect I provide electrical apparatus and circuits, these including electro-magnetic means for determining the firing of the gun, and, a contact device operated in accordance with the revolving propeller to control the circuits of said electromagnetic means to govern the firing of the gun.

In explaining the invention, I shall describe an embodiment thereof in connection with a machine gun or machine guns of the automatic type, that is, the discharge is rapid and automatic as long as the trigger member is pressed and held in the firing position, and in which the firing ceases when the trigger member is released or moved to the stop position. Also, the gun is shown mounted to fire through the plane of rotation of the propeller of a tractor aeroplane, so as to be operated by the pilot or driver of the machine.

The contact device for making and breaking the proper circuit connections at the right moment is preferably mounted upon the engine shaft or is otherwise driven in accordance with or dependent upon the speed of the propeller, and the electromagnetic device, for instance an electro magnet, is positioned and arranged to move the trigger of the gun or otherwise posi tlvely control the fire. In the mechanism shown the arrangement is such that the trigger is moved positively each way by the electromagnetic device, to permit and to stop firing.

The gun is preferably mounted so as to point forward over or past the engine through the propeller, but may be mounted in an suitable location, as desired. It is swive ed so as to be capable of movement in a horizontal plane for aiming, and a connection with the contact device is provided whereby the latter is adjusted in accordance with the angle of movement of the gun so as to change the timing correspondingly. The gun is also permitted a limited movement in the vertical plane so that the muzzle may be elevated for the purpose of sighting.

The invention also contemplates multiple machine gun firing in which two or more guns are mounted to fire between the blades of the same revolving propeller, each controlled b a contact device as above indicated an all manipulated by the same operator. For instance, if three guns be employed, the may all be mounted on the same swive ed member, the contact devices being so related that the guns fire (and cease firing) in succession so as not to injure the propeller blades. The arrangement is such that all of the guns are manipulated and aimed by grasping the handle or stock of any one, and also one or more of the guns may be put out of action if desired while the others remain in action. \Vhen multiple firing is provided for, the guns may discharge different material, for instance, one may fire ordinary bullets, one may fire incendiary bullets, and another signal devices.

The invention consists in the novel construction and arrangement of parts of the apparatus hereinafter described, and in the cooperating circuit connections thereof, reference being had to the accompanying drawings taken in connection with the following specification for a more complete understanding of the system and its operation.

In the drawings,

Figure 1 is a plan view of the gun mounting and arrangement, three machine guns being shown with the cooperatingcontacts for controlling the firing of the same, the engine for operating the propeller shaft being omitted to avoid complication-of the drawings;

Fig. 2 is a side elevation of the arrangement shown in Figure 1;

Fig. 3 is an end view on a larger scale of the timing shift arrangement shown in Fig. 2;

Fig. a'is a vertical longitudinal section through the commutator and timing shift gear;

Fig. 5 is a plan view corresponding to that shown in Fig. 1 showing the commutator and cooperating brushes;

Fig. 6 is a detail showing one of the contact devices or segments of the commutator and the insulating portion of the same;

Figs. 7, 8 and 9 are diagrammatic Views showing various relative positions of a ropeller blade with respect to the gun muzz es; and

Fig. 10 is a diagrammatic view showing the various elements of apparatus and their circuit connections.

Referring to the drawings, it will be seen that I have chosen for illustration a system vin which-- a plurality of machine guns are mounted for multiple firing between the revolving blades of a propeller. It will be understood, however, that a single gun may be employed or a number less or greater than three may be arranged iffound desirable.

' 1 indicates the propeller of an aerial ma chine, the propeller being shown in this in-.

stance as'having two blades 2 and 3. The,

propeller shaft is indicated at 4, the engine for driving said shaft being omitted from' the drawing and merely indicated by the legend in order to avoid unnecessary complications.

Mounted adjacent the engine or in any suitable location, is a support 5 upon which one or more machine guns may be mounted,

these guns being' three in number in this instance, designated A, B and C, respectively.

These guns are so mounted as to fire through the plane of revolution of the propeller and between the blades thereof when the propeller rotates.

In order to control the firing of said gun or guns, I provide an electromagnetic device mounted to control the trigger member of the gun. This electromagnetic device is shown in this instance as consisting of an electromagnet 6 for moving the trigger member 7 into the firing position, and an electromagnet 8 for moving said trigger member into the stop position. Each gun is provided with the usual grip portion 9 by which it may be manipulated, and when there are a plurality of guns all may be manipulated by grasping any one of the grips.

Various circuit connections with a suitable source of current, to be hereinafter more fully described, are provided, these being controlled by a contact device indicated broadly at 10 and comprising contact seg ments with cooperating brushes, one segment and brush being employed for controlling one of said electromagnets, while another segment with a cooperating brush is employed to control the other electromagnet of each electroma netic device. These segments are arranged with dead sections or insulations for deenergizing the respective circuits during a portion of the revolution in accordance with the rotation of the propeller. v

The gun mounting 5 is arranged for swivel movement in a horizontal plane so that the gun or guns may be moved laterally for the purpose of aiming; and also pivotally mounted for movemeent in the vertical plane so that the guns may be elevated slightly for the same purpose. This is accomplished by providing a swivel standard 11 arranged to turn within a sleeve 12 mounted upon the engine casing or other suitable fixed portion of the machine. Set screws 13, engaging an annular groove 14 in said standard 11, hold the standard securely upon said sleeve, but permit the ready removal of both the standard and the gun or guns for cleaning, repairs, etc.

For vertical movement, the standard is provided with a horizontal pivot 15, the joint being such that the muzzle cannot be depressed beyond a predetermined position, in which position it is held by a spring 16, but may be elevated to a desired'extent for the purpose of aiming.

The contact device 10, as above indicated, may be mounted in any suitable manner so as to rotate in accordance with the speed of the propeller, it being shown mounted upon the propeller shaft 4/ For the operation of the three machine guns indicated, the commutator comprises seven sections, section 17 being all metallic and constituting the common return for the various circuits in cooperation with contact brush 18. Segments 19 and 20 in cooperation with contact brushes 21 and 22, respectively, control the firing and stop circuits of machine gun C; segments 23 and 24 in cooperation with contact brushes 25 and 26 control the firing and stop circuits of machine gun B; and segments 27 and 28 in cooperation with brushes 29 and 30 control the firing and stop circuits of machine gun A.

The respective segments are not mounted directly upon shaft 4, but upon an insulating sleeve 31 which prevents electrical contact between the said shaft and the contact sections of the segments. The entire structure is bound together by tie bolts 32, and secured to the shaft by a set screw 33 or other form of key or spline. Set screw 33 is insulated from segment 28 by bushing 34.

The contact brushes are mounted in pairs upon rigid stub shafts so that said brushes may be either applied to or removed from contact with their respective segments at will. Such shafts are shown at 35, upon which brushes 25 and 26 are mounted; shaft 36 upon which brushes 29 and 30 are mounted; and shaft 37 upon which brushes 18, 21 and 22 are mounted. The ends of these respective shafts are seated in and pass through a two-part gear, mounted upon sleeve 39, which surrounds the shaft 4 and is prevented from turning by an arm 40 secured to any suitable fixed portion of the frame. Part 41 of the two-part gear is mounted upon and carried by a boss 42 of part 38, and is provided with an annular flange 43 surrounding the periphery of part 38, to which it is rigidly secured by set screws 44 when adjusted in the proper relationship. Each of the shafts 35, 36 and 37 is provided with a reduced portion at its attaching end which passes through a perforation in part 38, so as to swivelly turn therein, and extends beyond said part through sector slots in part 41. The shaft 35 passes through sector slot 45; shaft 36 passes through slot 46 and shaft 37 passes through slot 47. By this means the respective shafts may have a turning movement in their swivel mounting in part 38, and parts 38 and 41 of the two part gear may be adjusted angularly with respect to each other to change the relationship ofsaid shafts, and consequently the brushes carried thereby, with the two-part gear as a whole.

Each of said shafts 35, 36 and 37 is provided with an operating arm, indicated at 48, 49 and 50 respectively, each of said arms being engaged by a finger carried upon a rotatable sleeve 51 having shaft 4 as a center of movement. Said sleeve 51 is controlled in any suitable manner for the purpose of bringing the contact brushes into and out of engagement with thesegments of the commutator, as shown, this control consisting of a spring 52 secured at one end to part 41 of the two-part gear and at the other end to an arm 53. For movement in the other direction, electromagnets 54 act upon arm 53, which constitutes the armature of the electromagnets 54. Preferably a pin and slot connection between the levers 48, 49 and 50 and their respective operating fingers, is provided.

In order that the commutator segments may be properly adjusted when building up the commutator, the tie bolts 32 occupy segment slots in the respective segments, such a slot being shown in dotted lines at 55 in Fig. 3. Also, in order to completely insulate the segments from the frame of the machine, insulation 56 is provided between the end commutator segment and part 38 of the twopart gear.

Part 41 of the two-part gear has a toothed portion 57 which meshes with gear 58 carried by and secured to the swivel standard 11, so that any movement of said gear 58 by the turning of the gun or guns in a horizontal plane will' be communicated to gear 57 and hence will adjust the relationship between the contact brushes and the commutator segments.

Referring now to Fig. 10, where the apparatus and circuit connections are diagrammatically indicated, it will be seen that for the purpose of more conveniently tracing the circuits the segments of the commutator are shown concentric, and of different radii. The machine guns A, B and C are indicated in dotted lines in side elevation and in solid lines in rear elevation. The propeller blade is shown in various ositions with respect to the muzzles of t e guns.

Conductor 59 leads from battery 60 to switches a, b and 0 upon the respective guns, these switches being held normally open by their springs, but adapted to close the circuit from said conductor 59 to conductor 61 which is in connection with one side of each of the firing magnets 6. 62 leads from the other terminal of the firing magnet 6 of gun A to brush 29, which engages commutator segment 27; conductor 63 leads from the other terminal of firing magnet 6 of gun B to brush 25 engaging commu tator segment 23; and conductor 64 leads from the other side of firing magnet 6 of gun C to brush 21 engaging segment 19 of the commutator, These circuits are respectively provided with cutout switches a, b, c, by which said firing magnets, or two or more of them, are put out of action.

These circuits also may be provided with condensers 0. 6 0?, which are bridged across these commutator segments and their respective brushes for the purpose of eliminating the spark at the break and causing an instant break of the circuit when a brush leaves a segment. The commutator and brushes Conductor,

may also be immersed in oil for the same purpose.

The common return for the above mentioned circuits is through brush 18 and commutator segment 17 and wire 65 to battery.

In a similar manner the fire stop magnets 8 of the respective guns A, B and C are connected with conductor 61 on the one side, and by conductors 66, 67 and 68 with brushes 30, 26 and 22 respectively, which engage respectively segments 28, 2a and 20.

Each gun is provided with an additional switch 0 b 0 respectively, for closing the circuit of electromagnets 54: through conductors 69, 70 and 71.

The operation of the system will now be understood by a. consideration of the apparatus and circuits shown in Fig. 10. The propeller shaft 4: is assumed to be turning in the direction of the arrow, and the propeller blade is shown as being in front of the muzzle of gun C.

Vhenthe operator grasps the grip portion 9 of any one of the three guns, let us suppose for instance gun A, he thereby pushes in and closes switch a and also he places his finger upon the arm of switch a, indicated in the position of a normal gun trigger. Two circuits are thereby closed, the first starting from battery 60. wire 71, elect-romagnets 54, wire 69, switch a and return the battery by wire 70. This energizes electromagnets 54 which by attracting arms 53 cause the partial rotation of shafts 35, 36 and 37 and thereby place all of the contact brushes into engagement with the commutator. The other, or firing circuit may be traced from battery through wire 59, switch a, wire 61, whence the circuit will be' complete through the respective firing magnets 6 of guns A. B and C, through wires 62, 63 and 61, when the contact segments of the commutator are engaged by their respective brushes, it being assumed that switches lb, 7) and c are in the closed position. The circuit of each of said firing magnets will be completed through common return segment 17 of the commutator and brush 18 to wire 65. In the position of the propeller shown, the propeller has passed the guns A and B and therefore these guns are assumed to be firing, as shown by the position of the trigger member 7 of both guns. Blade 3 of the ropeller is shown in the line of fire of gun and in this position brush 21 has engaged commutator segment 19 and thereby closed the firing circuit of gun C as follows: battery, 60, wire 59, switch a, wire 61, firing magnet 6 of gun C, wire 64, brush 21, commutator segment 19 and return to battery by common return segment 17, brush 18 and wire 65. This will attract trigger member 7 of gun C and this gun will therefore begin to fire, and the firing will start as soon as the lag of the parts is overcome, during which time the blade moves out of line of the barrel of gun C, and will continue to fire until said trigger member is moved into the stop. position.

This it may do in response to the action of spring c, or this spring may be omitted'and the movement may be caused entirely by stop magnet 8, guns A and B being also provided with corresponding springs ac and b when desired.

The exact time when commutator segment 19 engages brush 21 may be made at any preferred instant in the cycle of movement of the propeller blade with respect to gun C, depending upon the distance of the propeller blade from the muzzle of the gun, and the range of speeds of the propeller within which it is desirable to operate. In most instances thecontact will be closed before the propeller blade leaves the line of fire, as there will be a slight lag in the operation of the firing magnet and also a brief interval will be required for the bullet to reach the plane of the propeller. Such timing may be very accurately adjusted in the building up of the commutator so that the desired result will be obtained with the greatest precision.

By an inspection of Fig. 10, it will be seen that the propeller positions are indicated by the broken lines connecting the center of rotation with the respective guns, and that brush 21 of gun C has progressed only a short distance on its segment, brush 25 of gun B has progressed further along on its segment, and brush 29 has progressed still further along on its segment. In like manner the brushes 22, 26 and 30 have engaged the insulation portion of their respective segments so that the stop magnets of the respective guns have been deenergized. In order to insure the proper interval for the energization of the respective firing magnets, it is desirable to have the circuit of each of said firing magnets closed before the corresponding stop magnet is deenergized, and this is effected preferably by having the conductive portion of each firing magnet segment overlapping the conductive portion of each stop magnet segment. This is illustrated diagrammatically in Fig. 10.

Returning now to gun C it will be observed that the brush 22 has passed off of segment 20 and the circuit of stop magnet 8 of gun C has been deenergized. This circuit was as follows: Battery 60, conductor 59, switch 0a,. conductor 72, stock magnet 8, gun C, conductor 68, brush 22, commutator segment 20 and return by segment 17, brush 18 and wire 65. hen the propeller and consequently the commuator have rotated so as to bring blade 3 of the propeller into the position ap-.

proaching gun C, the circuit just traced will be closed and immediately thereafter the circuit above traced of firing magnet 6 ofgun C will be deenergized, thereby causing gun C to cease firing. As shown in Figure 10, the firing circuit is in condition for operation at the time when the propeller blade is opposite the gun. The movement of the parts to firing position has just been completed. The blade is revolving rapidly and a time interval is necessary within which the movement of electrical parts can take place. It is this time element or lag which prevents bullets from damaging the propeller. It has been definitely ascertained that when the parts are theoretically in firing position. with the blade immediately in front of the gun, the actual firing cannot take place until an instant later during which instant the propeller moves from in front of the gun. By using the propeller in the position shown in Fig. 10, the firing takes place immediately after the blade leaves the position shown and firing ceases just before the next blade approaches the gun. It will be understood that the exact relationship between the closing of the firing magnet circuit and .the. breaking of the stop magnet circuit, and vice versa, may be arranged as found most effective.

In the system as shown, the arrangement is such that the firing magnet is energized once during the revolution of the propeller, that is. the firing is upon one side of the pro peller blade only. This is for the reason that in practice the maximum speed of revolution is approximately 1600 per minute, and it would be impracticable with any single unit machine gun now known to fire even at this rate, the usual rate being not over 1200 shots per minute. Of course when a gun is designed, or a combination of guns so arranged. as to shoot with greater rapidity, this relationship may change and it may be possible to fire more than once during a revolution on one side of blade of propeller at its maximum speed.

In such a system, also, it will be observed that each gun fires from the time the given blade of the propeller passes out of firing line until the other blade has almost reached the firing line, less than a half revolution, and the gun is silent during the remainder of the revolution. Hence, the conductive portion of each firing segment of the commutator must be less than 180. For similar reasons, the conductive portion of each stop segment will be greater than 180.

Referring now to Figs. 7, 8 and 9, the propeller blade 3 in Fig. 1 is shown approaching gun A, and this gun has therefore just ceased firing. guns B and C still remaining active. In Fig. 8, blade 3 has just passed before gun A and is just approaching gun B, so that gun A has resumed firing and gun B has ceased to fire. In Fig. 9, guns A and B are firing and gun C is just ceasing to fire.

The arrangement of commutator segments and circuits for the other guns is the same or similar to those for gun C, as above traced in the description of operation.

From the above, it will be understood that the entire system may be controlled from the grip of any one of the guns, and also all three guns may be simultaneously moved laterally in a horizontal or vertical plane for the purpose of aiming. When so moved, the brushes will be shifted on the commutator to change the timing in accordance with the direction and extent of movement, this being shown by an inspection of Fig. 1 when considered in connection with Figs. 3 and 4. If the movement is contrary to the direction of movement of the propeller blade, the timing will be changed to make the operation earlier, and if moved in the opposite direction it will be changed to cause the operation to be later.

It will be understood that many changes in details of construction and arrangement of parts may b made without departing from the invention, and all such I consider as falling within the scope of the invention and are intended to be included in the scope of the appended claims.

\Vhat I claim as new and desire to secure by Letters Patent of the United States is:

1. A circuit closer comprising a rotary disc of conducting material, a second rotary disc of insulating material and capable of rotary speed equal to the first disc, :1- conducting insert recessed into said insulating disc, and a pair of brushes adapted to bear upon the peripheries of said discs and adapted to be oscillated in the arcs of circles and relative to said discs.

2. A machine gun fire control system comprising in combination with an aerial propeller and a machine gun mounted to fire between the revolving blades thereof, electromagnetic means for causing the firing of said gun, electromagnetic means for preventing the firing of said gun, circuit connections and a source of current associated with said electromagnetic means, and a contact device timed according to speed of the propeller for operating said circuit connections.

3. A machine gun fire control system comprising in combination with an aerial propeller and a machine gun mounted to fire be tween the revolving blades thereof, electromagnetic means for causing and for preventing the firing of said gun, circuit connections and a source of current associated with said electromagnetic means, and a contact device having a conducting segment to complete the firing circuit and a conducting segment to complete the fire preventing circuit, said segments overlapping in time to energize one circuit before the other is deenergized.

4;. A machine gun fire control system comprising in combination with an aerial propeller and a machine gun of the automatic type mounted to fire between the revolving blades of said propeller, electromagnetic means for causing the continuous firing of said gun, electromagnetic means for preventing the firing of said gun, circuit connections and a source of current associated with said electromagnetic means, and a contact device timed according to the speed of said propeller for operating said circuit connections.

5. A machine gun fire control system comprising in combination with an aerial propeller and a machine gun of the automatic .type mounted to fire between the revolving blades of said propeller, said gun being provided with a trigger member, an electromagnet for moving said trigger member into firing position, a second electromagnet for moving said member into the stop position, circuit connections and a source of current associated with saidelectromagnets, and a contact device timed according to the speed of the propeller for operating said circuit connections to energize said first electromagnet at the moment when the blade is in front of the gun to permit firing between the revolving blades and to operate said circuit connections to energize said second electromagnet just prior to the moment when the blade passes in front of the gun cause cessation of firing.

6. A machine gun fire control system comprising in combination with an aerial propeller and a machine gun of the automatic type mounted to fire between the revolving blades of said propeller, said gun being provided with a trigger member, an electromagnet for moving said trigger member into firing position, a second electromagnet for moving said member into the stop position, circuit connections and a source of current, associated with said electromagnets, and a contact device timed according to the speed of the propeller for operating said circuit connections to energize said first mentioned electromagnet to fire between the revolving blades and to energize said second electromagnet to cause cessation of firing while a blade is passing the line of fire.

7. A machine gun fire control system comprising in combination with an aerial propeller and a machine gun mounted to fire between the revolving blades thereof, electromagnetic means for controlling the firing of said gun, circuit connections and a source of current associated with said electromagnetic means, a rotary commutator and cooperating brushes for operating said circuit connections, and electromagnetic means controlled from said gun for determining the application of said brushes to said commutator.

8. A machine gun fire control system coma rotary commutator and cooperating brushes for operating said circuit connections, an electromagnet mounted adjacent said commutator for determining the application of said brushes to said commutator, and a control circuit including said handle grip contacts and said electromagnet.

9. A machine gun fire control system comprising in combination with an aerial propeller and a machine gun swivelly mounted for lateral movement in aiming and arranged to fire between the revolving blades of said propeller, electromagnetic means for controlling the firing of said gun, circuit connections and a source of current associated with said electromagnetic means, a contact device timed according to the speed of said propeller for operating said circuit connections, and a connection between said gun and said contact device for altering the timing in accordance with the lateral movement of said gun.

10. A machine gun fire control system comprising in combination with an aerial propeller and a machine gun swivelly mounted for lateral movement in aiming and arranged to fire between the revolving blades of said propeller, electromagnetic means for controlling the firing of said gun, circuit connections and a source of current associated with said electromagnetic means, a rotary commutator operated in accordance with the speed of said propeller, brushes for said commutatorcooperating with said circuit connections for controlling the firing, and a gear connection between the swivel mounting of said gun and said commutator for shifting the relation between said brushes and said commutator to alter the timing in accordance with the lateral movement of the gun.

11. A machine gun fire control system comprising in combination with an aerial propeller and a machine gun swivelly mounted for lateral movement in aiming and arranged to fire between the revolving blades of said propeller. electromagnetic means for controlling the firing of said gun, circuit connections and a source of current associated with said electromagnetic means, a rotary commutator operated in accordance with the speed of said propeller, a two-part gear adjacent said commutator, brushes for said commutator swivelly mounted upon said two-part gear, means for rocking said brushes on said swivel connection to bring said brushes into or out of contact with said Ill commutator, and a gear associated with the mounting of said gun and meshing with said two-part gear for shifting the relation between said brushes and said commutator to alter the timing in accordance with the lateral movement of the gun.

12, A machine gun fire control system comprising in combination with an aerial propeller and a machine gun swivelly mounted for lateral movement in aiming and arranged to fire between the revolving blades of said propeller, electromagnetic means for controlling the firing of said gun, circuit connections and a source of current associated with said electromagnetic means, a rotary commutator operated in accordance with the speed of said propeller, a two-part gear adjacent said commutator, brushes for said commutator swivelly mounted upon one member of said gear, means carried by the other member of said gear for rocking said brushes on said swivel connection to bring said brushes into or out of contact with said commutator, means for adjusting the relative positions of said gear members, and means for moving said gear as a whole in accordance with the lateral movement of the gun to shift the relation between said brushes and said commutator.

13. A machine gun fire control system comprising in combination with an aerial propeller and a machine gun swivelly' mounted for lateral movement in aiming and arranged to fire between the revolving blades of said propeller, electromagnetic means for controlling the firing of said gun, circuit connections and a source of current associated with said electromagnetic means, a rotary commutator timed to revolve in accordance with the speed of said propeller, cooperating brushes for said commutator associated with said circuit connections, a gear connection between the swivel mounting of said gun and the mounting of said brushes for altering the timing in accord ance with the lateral movement of the gun, and electromagnetic means mounted upon said gear connection for determining the application of said brushes to said commutator.

14. A machine gun fire control system comprising in combination with an aerial propeller and a plurality of machine guns mounted to fire between the revolving blades of said propeller, each of said guns having a grip portion for an operator, electromagnetic means for controlling the firing of each gun, circuit connections for each of said electromagnetic means and a source of current associated therewith, a contact device timed according to the speed of said propeller for operating said circuit connections, and circuit controlling contacts mounted on the grip portion of each gun for placing the entire system of all said guns in action.

15. A machine gun fire control system comprising in combination with an aerial propeller and a pluralit of machine guns mounted to fire between t e revolving blades of said propeller, each of said guns having a grip portion for an operator, electromagnetic means for controlling the firing of each gun, circuit connections for each of said electromagnetic means and a source of current associated therewith, a contact device timed according to the speed of said propeller for operating said circuit connections, circuit controlling contacts mounted on the grip portion of each gun for placing the entire system of all said guns in action, and a cut-out switch in the circuit of each of said electromagnetic devices whereby one or more of the same may be put out of action.

16. A machine gun fire control system comprising in combination with an aerial propeller and a machine gun mounted to fire between the revolving blades thereof, electromagnetic means for causing and for preventing the firing of said gun, circuit connections and a source of current associated with said electromagnetic means, and a contact device having a conducting segment to complete the firing circuit when the propeller blade is in line with the gun and a conducting segment to complete the fire preventing circuit, said segments overlapping in time to energize one circuit before the other is deenergized.

17. A machine gun fire control system comprising in combination with an aerial propeller and a machine gun mounted to fire between the revolving blades thereof, of electromagnetic means for causing the firing of said gun, electromagnetic means for preventing the firing of said gun, circuit connections and a source of current associated with said electromagnetic means, and a contact device timed according to speed of the propeller for operating said circuit connections and to complete the firing circuit and initiate the actuation of the parts for firing when the blade is directly in line with the gun.

18. A machine gun fire control system comprising in combination with an aerial propeller and a plurality of machine guns mounted to fire between the revolving blades thereof, separate control means for controlling the firing of each of said guns, connections for each of said guns associated with said control means, and an operating device having separate actuating means each timed in accordance with the speed of said propeller for operating through the said connections each respectivevcontrol means so that firing may occur only when said blades are out of line of fire of the respective guns.

19. A machine gun fire control system comprising in combination with an aerial propeller and a plurality of machine guns mounted to fire between the revolving blades thereof, separate control means for controlling the firing of each of said guns, connections for each of said guns associated with said control means, and a rotary operating device having separate actuating means cooperating with said control means through said connections and timed according to the speed of said propeller to control the firing of each of said guns.

20. A machine gun fire control system comprising in combination with an aerial propeller and a plurality of machine guns mounted to fire between the revolving blades thereof, each of said guns having a grip portion for an operator. control means for controlling the firing of each gun, connections for each of said control means, an operating device timed according to the speed of said propeller for operating through said connections each I'GSpQCtlX G control means, and means mounted on the grip portion of each gun and co-acting with said connections and said control means for placing the entire system of all of said guns in action.

21. A machine gun fire control system comprising in combination with an aerial propeller and a plurality of machine guns mounted to fire between the revolving blades thereof, each of said guns having a grip portion for an operator, control means for controlling the firing of each gun, connections for each of said control means, an operating device timed according to the speed of said propeller for operating through said connect-ions each respective control means, means mounted on the grip portion of each gun and co-acting with said connections and said control means for placing the entire system of all of said guns in action, and disconnecting means for putting out of action one or more of said control means.

In testimony whereof I have hereunto set my hand.

DANIEL G. EDWARDS. 

